Product introduction
GW7B series Switch Disconnector is a kind of outdoor HV electricity transmission equipment’s at three-phase AC frequency of 50Hz/60Hz. it is used for breaking or correcting HV lines under no loads so that these lines can be changed and connected and the way the electricity runs is changed. in addition, it can be used to exercise safe electrical insulation for such HV electric apparatuses as bus and breaker. The switch can open and close inductance/capacitance currant and is able to open and close the bus to switch current.
This product has three posts with horizontal open breaks. JW10 grounding switches may be attached to the product at one or two sides 72.5-252kV Switch Disconnector adopts C2 or SRCJ2 manual actuator to realize the tri-pole linkage. The earthing switch adopts CS11 or SRCR manual actuator to actualize tr-pole linkage,.363kV disconnect switch adopts SRCJ2 motor's actuator to realize the single pole operation; while the earthing switch takes SRCS manual actuator or SRCJ2 motor's actuator to realize the single pole operation and also tri-pole linkage.
This product has been verified by the Chinese competent authority as having uniqueness in design and reaching international advanced level of similar products.
GW7B Switch Disconnector comprises three single poles and actuator. Each single pole is made of a base, post insulator and conductive part. Three insulating posts are installed onto a long base, with two static contacts mounted at both ends to fix the top of the insulating post, and the conductive knife switch mounted onto the top of the rotating insulating post in between.
The actuator drives the rotating post in the middle to bring the conductive knife switch circumgyrate to open or close the breaker by contacting or detaching the static contacts fixed on the both ends of the post, Two horizontal insulating open breaks in series will appear at the closing moment.
In the opening and closing process, the conductive knife switch will horizontally swing and auto-rotate, with the aid of the turnover mechanism, to reduce the operating force and impact that occur in the opening and closing process and to improve the contact’s ability self-cleaning.
Main characteristic
1、 The Switch Disconnector is of the turnover-type, and the conductive tube will move in two steps. At the closing moment, the conductive tube will rotate by some 70" on the horizontal surface, When the contacts at both ends are blocked up after having been placed in the static contact base, the turnover mechanism will drive the conductive tube to auto-rotate by about 45° when the movable contact will be in reliable contact with the touch finger. This process requires small operating force, thus causing no impacts on the insulators fixed at both ends. The main contact has the self-cleaning ability.
2、 One end of the U-shaped finger within the static contact is fixed onto the contact base, forming a fixed connection and ensuring the reliable conduction; while the other end will produce contact pressure on the movable contact as a result of the influence of external spring and the own elastic force of the contact finger, and the gripping force will automatically increase when the short-circuit current passes through the contact. The contact spring is made of stainless steel and is equipped with insulating gasket, The spring will not corrupt nor shunt.
3、 Provide one-key sequential control "double confirmation" function expansion.
4、 The rotating parts of the disconnect switch are designed to be free of maintenance. The rotating base is designed into a closure structure which denies the access of moisture, dust and harmful gases so that the low-temperature lubricating cream within the bearing will not run off or harden.
5、 363kV and above earthing switch is in the single-arm standing and openable structure, with the structurally simple plug-type contact, The conductive rod for grounding will move in twosteps at the moments of opening and closing. At the moment of closing, the conductive rod will rotate vertically and rise up lo the fixed contact, and then automatically plug itself into the star-shaped contact, By doing so, the contact will be made reliable and be able to sustain the heavy short-circuit current.
Main technical parameters
Order notice
Product model, rated voltage, rated current, rated short-time withstand current, creepage distance and method of combination must be specified at the goods ordering time;
The methods of attaching earthing switches to Switch Disconnectores (left, right and both left and right);
Note: the way to judge the method of grounding: when one faces the name plate, the left grounding will be confirmed if the earthing switch is at the left hand side, and right grounding if at the right hand side;
The actuator's model and name, motor's voltage, control voltage and the number of contacts for auxiliary switch;
Current transformers are ordered by purchasers; however, it must be ensured that fixed contacts can be mounted onto such transformers:
When the Switch Disconnector is used at the incoming and outgoing terminals of the substation in the double loop parallel overhead power transmission line, if the earthing switch requires the opening/closing induction current, then such requirement shall be specified, Besides, the parameters and the side at which the earthing switch is set shall be defined. (Special notice: Not all earthing switches attached to the earthing switches and disconnect switches at the substation shall require the opening/closing induction current.)
